Flora of New Zealand Series

Holotype: New Zealand. Wellington. Ruahine Range on Nothofagus bark. W. Colenso 4548, H-NYL 30829.

Thallus squamulose, dispersed on a thin, black prothallus. Squamules flattened, small-foliose at margins, simple, flattened globose to ± stellate, coralloid to 1 mm wide, congested, ascending, laciniate-coralloid centrally, apices lobulate and deflexed, tightly packed in a coralloid crust, ± terete or laterally flattened, yellowish or greenish-buff, not pale green or whitish as in P. asperellum, matt to rather granular, faintly whitish-pubescent at apices. Cephalodia pale blue or brownish-grey, crowded, squamulose, between thalline squamules. Lower surface white at margins, yellow-brown centrally, without thick tomentum, arachnoid, noticeably striate as in P. araneosum, attached to substrate by medullary hyphae, rhizines absent. Apothecia sessile, plane, round at first, becoming convoluted-irregular with age, 0.5-2.5 mm diam., margins crenate- eroded, rather thick, disc chestnut-brown or red-brown, matt, smooth, plane to undulate, not pruinose, fissured or gyrose-etched, thalline exciple wrinkled-corrugate, areolate-scabrid. Ascospores 15-21 × 8-10 µm.

N: Wellington (Ruahine Ra.). Probably more widely distributed but known with certainty only from the type collection.

Endemic

This species appears to be very similar to P. athroophyllum which is widely distributed in mainly lowland coastal habitats in South I. However, there is a distinct chemical difference between the two species and P. coralloideum is kept apart from P. athroophyllum pending further collections and close comparison of populations of both taxa.